A common paper glider/sailplane, folded from standard A4 or letter paper by following the steps shown in FIG. 11 and known as the Eagle design or Nakamuru lock design, can glide for a few seconds following hand launching into the air.
The invention concerns an electrical power conversion kit/unit which can be mounted on such common airplane design to provide adequate propulsion to transform the paper sailplane into a free flight, soaring paper airplane.
A prior electric power conversion unit, disclosed in my prior patent publication 2008/0125002, published May 29, 2008, and comprising a battery housing nose-piece connected by a wire receiving conduit to a rear electric motor driving a propeller is secured to the leading edges of the paper airplane wings on each side of a central (fuselage) crease by a nose-piece clip portion. The clip portion has a pair of leaf springs extending rearwardly in spaced-apart, coplanar, side-by-side relation below the battery holding housing portion. A vertical fold/paper (fuselage) crease is received between the leaf springs which exert a vertical clamping force on leading edge portions of the horizontal wings on each side of the crease.
A disadvantage of my prior approach is that the clip exerts only a vertical clamping force on the paper wings which can be insufficient for reliable retention during powered flight and does not reliably prevent yaw of the power unit relative to the paper plane when under power, as torque is applied to the power unit as a result of the rotation of the propeller.